[Bindings] Add DCHECK to confirm RemoteWindowProxy is not used for main frame

third_party/WebKit/Source/bindings/core/v8/RemoteWindowProxy.cpp

 /*
  * Copyright (C) 2008, 2009, 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 29 matching lines @@
 #include "platform/ScriptForbiddenScope.h"
 #include "platform/instrumentation/tracing/TraceEvent.h"
 #include "v8/include/v8.h"
 #include "wtf/Assertions.h"
 
 namespace blink {
 
 RemoteWindowProxy::RemoteWindowProxy(v8::Isolate* isolate,
                                      RemoteFrame& frame,
                                      RefPtr<DOMWrapperWorld> world)
-    : WindowProxy(isolate, frame, std::move(world)) {}
+    : WindowProxy(isolate, frame, std::move(world)) {
+  DCHECK(!this->frame()->isMainFrame());
+}
 
 void RemoteWindowProxy::disposeContext(GlobalDetachmentBehavior behavior) {
   if (m_lifecycle != Lifecycle::ContextInitialized)
     return;
 
   if (behavior == DetachGlobal && !m_globalProxy.isEmpty()) {
     m_globalProxy.get().SetWrapperClassId(0);
     V8DOMWrapper::clearNativeInfo(isolate(), m_globalProxy.newLocal(isolate()));
 #if DCHECK_IS_ON()
     didDetachGlobalObject();
@@ skipping 61 matching lines @@
 
   // The global object, aka window wrapper object.
   v8::Local<v8::Object> windowWrapper =
       globalProxy->GetPrototype().As<v8::Object>();
   v8::Local<v8::Object> associatedWrapper =
       associateWithWrapper(window, wrapperTypeInfo, windowWrapper);
   DCHECK(associatedWrapper == windowWrapper);
 }
 
 }  // namespace blink